عادة أقلم الساق عندما يذبل النبات المنزلي.

Because Arabic verbs already show the subject.

أقلم means I prune / I trim.
The prefix أ- on the imperfect verb marks first person singular, so أنا is not required.

• أقلم = I prune
• أنا أقلم = I prune / I do prune

Including أنا is possible, but it usually adds emphasis or contrast. In a normal sentence, Arabic often leaves it out.

It is the imperfect (non-past/present) form of the verb قلّم.

• past: قلّم = he pruned / trimmed
• imperfect: أقلم = I prune / I am pruning
• dictionary/root meaning here: to prune, trim, clip

In this sentence, the imperfect is used for a habitual action, especially because of عادة (usually), so the sense is:

• I usually prune...

not necessarily I am pruning right now.

In fully vowelled Arabic, it would be pronounced ʾuqallimu.

Without short vowels, it is written أقلم, which can be hard for learners to interpret. The important thing is that this verb comes from قلّم with a doubled middle consonant in its underlying form.

A helpful rough pronunciation is:

• ʾu-qal-lim

not simply aqlam.

In normal unvowelled text, learners have to recognize the word from context and vocabulary knowledge.

عادة means usually or habitually here.

It functions like an adverb, telling you that the action happens regularly:

• عادة أقلم الساق = I usually prune the stem

Arabic often places words like عادة near the beginning of the sentence, but other positions are also possible depending on style and emphasis.

الساق literally means the stem or the stalk.

It is definite here because Arabic often uses the definite article where English may use:

• the
• a generic noun
• or something understood from context

So أقلم الساق can mean:

• I prune the stem
• or more naturally in context, I prune the plant’s stem

Arabic sometimes prefers a simpler definite noun where English might choose a possessive expression.

Yes. ساق النبات means the stem of the plant.

That version is more explicit because it directly links the stem to the plant. Compare:

• أقلم الساق = I prune the stem
• أقلم ساق النبات = I prune the plant’s stem
• أقلم ساق النبات المنزلي = I prune the houseplant’s stem

The original sentence is still understandable, but ساق النبات would sound more specific.

عندما means when and introduces a time clause.

So:

• عندما يذبل النبات المنزلي = when the houseplant wilts

This works well for a repeated or general situation, especially with عادة.

By contrast:

• إذا often means if / when in conditional or general future contexts.

For example:

• إذا ذبل النبات، أقلم الساق = If/When the plant wilts, I prune the stem

So عندما is a straightforward choice for when, while إذا can sound more conditional.

Arabic uses the imperfect after عندما very naturally, especially in general, repeated, or non-past situations.

Here the meaning is habitual:

• I usually prune the stem when the houseplant wilts

So يذبل does not have to mean is wilting right now. It can also mean:

• wilts
• does wilt
• becomes wilted

The imperfect is very common in statements about repeated actions and general truths.

Because the subject is النبات المنزلي, and نبات is grammatically masculine singular.

So the verb must agree with it:

• يذبل النبات = the plant wilts

If the subject were a feminine singular noun like النبتة, then you would say:

• تذبل النبتة = the plant wilts

This is an important point: Arabic agreement follows the grammatical gender of the noun, not necessarily what feels natural in English.

Because adjectives normally come after the noun in Arabic.

So:

• النبات = the plant
• المنزلي = domestic / home / indoor

Together:

• النبات المنزلي = the houseplant / indoor plant

This is the standard Arabic noun + adjective order.

Because Arabic adjectives agree with the nouns they describe in definiteness as well as gender and number.

Since النبات is definite, the adjective must also be definite:

• النبات المنزلي = the houseplant

If the noun were indefinite, the adjective would also be indefinite:

• نبات منزلي = a houseplant

This matching is very important in Arabic.

منزلي is an adjective meaning something like:

• domestic
• home
• household
• indoor (depending on context)

In النبات المنزلي, the most natural English meaning is houseplant or indoor plant.

It comes from منزل (house, home) plus the adjectival ending that creates a nisba adjective:

• منزل = house/home
• منزلي = home-related, domestic, household

Yes, it is natural and understandable.

Arabic allows some flexibility in word order. This sentence begins with عادة to foreground the habitual meaning:

• عادة أقلم الساق... = Usually, I prune the stem...

A few other possible word orders are also valid, depending on emphasis, for example:

• أقلم الساق عادةً عندما يذبل النبات المنزلي
• عندما يذبل النبات المنزلي، أقلم الساق عادةً

The original version is perfectly normal.

In formal fully vocalized Arabic, yes, there are case/mood endings. But in most real spoken reading, and even in much careful Modern Standard Arabic, final short vowels are often not fully pronounced unless the context is very formal.

For example, in full inflection, you might analyze it roughly as:

• عادةً أُقَلِّمُ الساقَ عندما يذبلُ النباتُ المنزليُّ

But many learners first focus on the main words and structure without stressing every ending in ordinary reading.

So:

• good for grammar study: learn the endings
• good for practical reading: recognize that many texts omit them

It describes a repeated habit.

The biggest clue is عادة (usually). Both verbs are in the imperfect, which fits a habitual meaning:

• عادة أقلم... عندما يذبل...
• I usually prune... when ... wilts

Without عادة, the sentence could still be interpreted as a general pattern, but عادة makes the habitual meaning much clearer.

Yes, in this context, whenever is a very helpful English gloss.

Because the sentence is habitual, these English versions are all close:

• I usually prune the stem when the houseplant wilts.
• I usually prune the stem whenever the houseplant wilts.

The Arabic عندما itself basically means when, but because the whole sentence is habitual, whenever can sound more natural in English.